Can anyone offer advice on calculating an appropriate full-time salary based on a freelance rate? I’m transitioning from freelance to full-time and understand the differences in benefits reflect directly on the pay. I’m trying to better understand how to be fair to both myself and my employer.
Has anyone had any experience with this? Is there any simple way to approach this?
Yeah,
Simple answer, What do you need to maintain your current lifestyle, and how much are you worth to the development team. Also take into consideration the average pay/benifits for the area and industry catagory.
Unfortunately there’s no algebraic formula that will provide the answer. There are too many intangibles that make it impossible to create a (freelance rate)x(M) = (salary) where (M) represents some kind of finite number that works flawlessly in every case…but I don’t think you were really looking for that. 
Knowing your value is one of the hardest things to determine, no matter your profession. And nearly all the designers I know undervalue themselves. Salary terms are always up for negotiation. You can make the process as simple of as complex as you like. It’s up to you.
If you have a number that you feel comfortable with, and you can get it, then you’re good to go. If your goal is to maximize your salary, (regardless of wants or needs) that’s where you need to do more extensive research in order to gauge what you’re truly worth to your potential employer. There are lots of in-between scenarios as well…just highlighting the extreme cases.
No matter how you want to proceed, the ball is in your court at the moment. Your employer wants to hire you full time and make you a permanent addition to the team. This is after they have been able to “test you out” with the freelance option. They see you as being valuable asset, and want to retain that value. This is in contrast to the “new hire” option of going after someone they aren’t familiar with, which would involve a higher degree of risk from their perspective…
40 hours a week x 52 weeks per year = 2080 hours
Your hourly rate * 2080 = yearly salary
Example: $25/hr * 2080 = $52,000/yr
Compare that number to the cost of living for where you plan on living and adjust accordingly. This should get you in the ballpark.
Make sure that you get a clear idea of what benefits your employer is offering.
For example, what is the quality of the Medical Coverage (if there is any).
Dental?
The types of things that a freelance doesn’t have, and therefore should be compensated for (at least partially) in pay.
Just another factor.
Thanks for everyone’s replies so far.
For anyone interested, I found on Salary.com that your salary is about 70% of what an employer pays to have you on staff, while the other 30% goes towards insurance, social security, time off, etc.